This invention relates to mufflers for percussion instruments such as bass drums, and in particular to a muffler which is adjustable and does not change the pitch of the sound emanating from the percussion instrument as the degree of muffling is altered.
Mufflers for percussion instruments, such as drums and tomtoms, are well known. There are passive mufflers, which comprise pads or the like which are affixed to a drum head or membrane, and active mufflers, which bear against the drum head with varying degrees of intensity in order to alter the vibratory characteristics of the drum head, and therefore muffle the sound emanating from the drum.
Mufflers which apply pressure to the drum head must necessarily also alter the pitch of the sound emanating from the drum. This result is undesirable since a drum is normally considered to be a single tone instrument. In addition, most such active mufflers are located on the exterior of the drum, intruding into the playing area and often creating an unsightly adjunct to the drum itself.
Several mufflers have been developed for mounting substantially within the drum interior, thus avoiding detraction from the drum's exterior appearance. Such mufflers are shown, for example, in U.S. Pat. Nos. 573,320; 663,853; 2,499,616; 2,572,504 and 4,154,137. However, since the muffling device of each of these patents bears against the drum head, the pitch of the sound emanating from the drum is often changed depending on the amount of pressure with which the muffling device bears against the drum head. Also, the mufflers are composed of several mechanically connected metal parts, which can tend to rattle and loosen, adding extraneous noise. In addition, the degree of muffling is often difficult to ascertain independently without striking the drum head and listening to the muffled effect. Obviously, this testing procedure cannot be accomplished in the midst of a musical composition.